Table 2.
Diagnostic sensitivities and specificities of antigen combinations
| Groups /antigens | Sensitivity (%) | Specificity (%) | PPV (%) | NPV (%) |
|---|---|---|---|---|
| PTB‐SP versus HC | ||||
| A | 86.8 (33/38) | 80 (32/40) | 80.5 (33/41) | 86.5 (32/37) |
| B | 86.8 (33/38) | 80 (32/40) | 80.5 (33/41) | 86.5 (32/37) |
| C | 71.1 (27/38) | 70 (28/40) | 69.2 (27/39) | 71.8 (28/39) |
| A+B | 94.7 (36/38) | 72.5 (29/40) | 76.6 (36/47) | 93.5 (29/31) |
| A+C | 94.7 (36/38) | 70 (28/40) | 75 (36/48) | 93.3 (28/30) |
| B+C | 92.1 (35/38) | 62.5 (25/40) | 70 (35/50) | 89.3 (25/28) |
| A+B+C | 94.7 (36/38) | 62.5 (25/40) | 70.6 (36/51) | 92.6 (25/27) |
| TB‐DOT | 76.3 (29/38) | 85 (34/40) | 82.9 (29/35) | 79 (34/43) |
| PTB‐SN versus HC | ||||
| A | 55 (11/20) | 80 (32/40) | 57.9 (11/19) | 78 (32/41) |
| B | 70 (14/20) | 80 (32/40) | 63.6 (14/22) | 84.2 (32/38) |
| C | 65 (13/20) | 70 (28/40) | 52 (13/25) | 80 (28/35) |
| A+B | 85 (17/20) | 72.5 (29/40) | 60.7 (17/28) | 90.6 (29/32) |
| A+C | 85 (17/20) | 70 (28/40) | 58.6 (17/29) | 90.3 (28/31) |
| B+C | 90 (18/20) | 62.5 (25/40) | 54.5 (18/33) | 92.6 (25/27) |
| A+B+C | 90 (18/20) | 62.5 (25/40) | 54.5 (18/33) | 92.6 (25/27) |
| TB‐DOT | 60 (12/20) | 85 (34/40) | 66.7 (12/18) | 81 (34/42) |
| EPTB versus HC | ||||
| A | 68.8 (11/16) | 87.5 (35/40) | 68.8 (11/16) | 87.5 (35/40) |
| B | 56.2 (9/16) | 75 (30/40) | 47.4 (9/19) | 81.8 (30/37) |
| C | 56.2 (9/16) | 75 (30/40) | 47.4 (9/19) | 81.8 (30/37) |
| A+B | 87.5 (14/16) | 72.5 (29/40) | 56 (14/25) | 93.5 (29/31) |
| A+C | 81.3 (13/16) | 72.5 (29/40) | 54.2 (13/24) | 90.6 (29/32) |
| B+C | 81.3 (13/16) | 60 (24/40) | 44.8 (13/29) | 88.9 (24/27) |
| A+B+C | 93.7 (15/16) | 60 (24/40) | 48.4 (15/31) | 96 (24/25) |
| TB‐DOT | 62.5 (10/16) | 85 (34/40) | 62.5 (10/16) | 85 (34/40) |
A, Rv0222; B, Rv3403c; C, ESAT6/CFP10; EPTB, Extra‐pulmonary TB; HC, Healthy control; PTB‐SP, Smear‐positive pulmonary TB; PTB‐SN, Smear‐negative pulmonary TB.
Sensitivity (%) = number of patients positive by ELISA/total number of confirmed patients × 100. specificity (%) = 100 – number of control samples positive by ELISA/total number of control samples × 100. PPV (positive predictive value) % = number of the true‐positive samples/ sum of true‐and‐false positive samples × 100. NPV (negative predictive value) % = number of true‐negative samples /sum of true‐and‐false negative samples × 100.